Convert WebM videos to MP4 for phones and editors, free, no upload.
Open Video ConverterWebM is a web-first format using the VP8 or VP9 codec. It is great in browsers but is often rejected by phones, video editors, messaging apps and social uploads, which expect MP4. Converting WebM to MP4 with H.264 makes the clip play and import everywhere.
WebM uses VP8 or VP9, which MP4 does not accept, so SammaPix re-encodes to H.264 at a high-quality setting. The result is visually faithful and far more compatible.
| Format | File Size | Quality | Compatibility | Use Case |
|---|---|---|---|---|
| MP4 | Small to Medium | High (H.264) | Universal | Phones, editors, social |
| WebM | Small | High (VP9) | Modern browsers | Web embedding, streaming |
| MOV | Medium | High | Apple-centric | iPhone capture, editing |
| MKV | Medium | High | Players, media servers | Multi-track archives |
Open the WebM to MP4 converter
Click the button above or go directly to /tools/convert-video. No signup required- the tool is free and works instantly in your browser.
Drop your files
Drag and drop your WebM files onto the upload area, or click to browse. You can convert up to 20 files at once on the free plan (500 on Pro).
Download your MP4 files
Click Download on each file or use Download All as ZIP to save everything at once. All processing happens in your browser- nothing is uploaded to a server.
Complete privacy
Your files never leave your device. All conversion happens inside your browser using the Canvas API and WebAssembly.
Instant results
No upload, no queue, no waiting for a server. Conversion starts the moment you drop your files.
True batch processing
Convert up to 20 files at once on free (500 on Pro) and download them all as a ZIP. No signup required.
Always free
Core conversion tools are free forever. No watermarks, no file size caps on common formats, no account required.
Why convert WebM to MP4?
WebM plays in browsers but many phones, editors and apps do not accept it. MP4 with H.264 works everywhere, so converting makes your clip universally usable.
Does converting WebM to MP4 lose quality?
A re-encode is required because MP4 cannot hold VP8 or VP9. SammaPix uses a high-quality setting so the difference is not noticeable.
Is my WebM uploaded?
No. The conversion runs in your browser with WebCodecs. Nothing is sent to a server.
Ready to convert? It takes less than 10 seconds.
Open Video Converter